Method of treating ocular disorders with compounds found in harderian gland secretions

ABSTRACT

The present invention is directed to pharmaceutical compositions comprising compounds found in Harderian gland secretions, a method of treating dry eye in a human comprising ophthalmically administering an effective amount of a compound, e.g. a lipid compound, found in Harderian gland secretions, pharmaceutical compositions comprising said lipid compounds, as identified by characteristic chemical data and mass spectra of said lipid compounds, said lipid compound in essentially pure form, and an ophthalmic vehicle comprising a therapeutic agent and a compound present in the secretions of the Harderian gland, e.g. a lipid compound, found in the secretions of the Harderian gland, e.g. a rabbit Harderian gland.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/051,092, filed Feb. 23, 2016, which is a divisional of U.S. patentapplication Ser. No. 14/523,264, filed Oct. 24, 2014, now U.S. Pat. No.9,289,494, which claims the benefit of U.S. Prov. Appl. 61/906,487,filed Nov. 20, 2013, each of which is incorporated by reference in itsentirety.

BACKGROUND OF THE INVENTION 1. Field of Invention

The present invention relates to the use of compounds which are presentin the secretions of the Harderian glands of certain animals, e.g.rabbits, in the preparation of a medicament for treating “dry eye” orother ocular disorders. A further embodiment of the present inventionrelates to a method of treating a patient suffering from “dry eye” andrelated ocular disorders with said medicament.

2. Description of Related Art

The Harderian gland is a gland found within the eye's orbit which occursin vertebrates (reptiles, amphibians, birds and mammals) that possess anictitating membrane. The gland secretes fluid (mucous, serous or lipid)that varies between different groups of animals. Various reptiles,birds, and sharks, as well as mammals such as camels and polar bears,have a full nictitating membrane. It is often called a third eyelid. Inmany mammals, there is a small vestigial remnant of the nictitatingmembrane present in the corner of the eye. In some animals it acts as anaccessory to the lacrimal gland, secreting fluid that eases movement ofthe nictitating membrane. The gland may have several other functions,including that of a photoprotective organ, a location of immuneresponse, a source of thermoregulatory lipids, a source of pheromones, asource of saliva, and/or a site of osmoregulation.

The Harderian gland in rabbits is related to the nictitating membrane(from Latin nictare, to blink), which is a transparent or translucentthird eyelid present in some animals that can be drawn across the eyefor protection and to moisten the eye while also maintaining visibility.In rabbits and rodents, the Harderian gland secrets non-polar lipidsnear the surface of the eye which mixed with the tears of the lacrimalgland. Rabbits do not suffer from “dry eye” as do humans. It is believedto be the lack of protective fluids of the Harderian gland may makehumans more susceptible to “dry eye” and diseases associated with “dryeye.

Humans are subject to the development of damage to the cornea andconjunctiva as a result of insufficient tears or insufficientlubricating substances within the tears. This is a common problemincreasing with age and more marked in women than men. Various wettingagents and solutions commonly known as “artificial tears” are onlypartially effective in protecting tissues in patients with “dry eyes”.Alteration, deficiency or absence of the tear film may lead tointractable desiccation of the corneal epithelium, ulceration andperforation of the cornea, an increased incidence of infectious disease,and ultimately, severe visual impairment and blindness.

Dry eye is a disease of the tears and ocular surface resulting insymptoms of discomfort, visual disturbance, and a tear film thatinadequately protects the eye leaving potentially damaging conditionsfor the ocular surface. Keratoconjunctivitis is inflammation of thecornea and conjunctiva. Keratoconjunctivitis sicca (KCS) is chronic,bilateral desiccation of the conjunctiva and cornea due to an inadequatetear film.

Individuals suffering from tear film dysfunctions are diagnosed withkeratoconjunctivitis (KCS), for example Sjögren's Syndrome or simply“dry eye”. These lacrimal abnormalities are subdivided into four generalcategories:

1. Aqueous tear deficiencies most frequently responsible for dry eyestates, originating from lacirmal gland disorders including autoimmunedisease, congenital alacrima, paralytic hyposecretion or excretory ductobstruction.2. Mucin deficiency which is observed in conditions associated withtrachoma, thermal and chemical burns, hypovitaminosis A.3. Lipid abnormalities.4. Diminished eyelid function. (See U.S. Pat. No. 6,107,289).

Evaporative keratoconjunctivitis sicca is caused by loss of the tearfilm due to abnormally rapid evaporation which is a result of aninadequate oil layer on the surface of the aqueous layer of tears.Symptoms may result from an abnormal oil in the tear film.

Aqueous tear-deficient keratoconjunctivitis sicca is caused byinadequate tear volume while evaporative keratoconjunctivitis sicca(more common) is caused by accelerated tear evaporation due to poor tearquality. Aqueous tear-deficient keratoconjunctivitis sicca is mostcommonly an isolated idiopathic condition in postmenopausal women. It isalso commonly part of Sjögren's syndrome. It is secondary to otherconditions that scar the lacrimal ducts due to trachoma. It may resultfrom a damaged or malfunctioning lacrimal gland, HIV (diffuseinfiltrative lymphocytosis syndrome), local radiation therapy, orfamilial dysautonomia. A subset of the dryness symptoms is expressed asSjögren's syndrome, which is also a known “Sicca syndrome” and is asystemic autoimmune disease in which immune cells attack and destroy theexocrine glands that produce tears and saliva. Nine out of ten Sjögren'spatients are women and the average age of onset is late 40s, althoughSjögren's occurs in all age groups in both women and men. It is thesecond most common autoimmune rheumatic disease in the United States.Autoimmune rheumatic disorders include Rheumatoid arthritis A.

Patients suffering from dry eye report itching; burning; a gritty,pulling, or foreign body sensation; or photophobia. A sharp stabbingpain, eye strain or fatigue, and blurred vision may also occur. Somepatients note a flood of tears after severe irritation.

Artificial tears are used to relieve temporarily the symptoms ofdiscomfort associated with dry eye and sometimes blocking thenasolacrimal openings. Ideally the artificial tear or lubricant shouldprovide lubrication and moisture to the tear film and protect the ocularsurface.

Prior art compositions useful for administering medications into theeyes are generally effective, but many have the drawback of requiringfrequent administration and are often rapidly washed away by the naturalprocesses of the eye. The current prescribed therapeutic approach tomanaging KCS is the frequent application of artificial tear substitutesfor lubricating the anterior eye surface. Frequent artificial tears andlubricants may cause visual blurring and alter the ocular surface andchemistry of the tear film on the ocular surface.

Hypotonic solutions used for ocular irritation may flood the ocularsurface with water, enter the cells and produce a hypotonic artificialtear, which may leave the ocular surface with less water and moreirritated than before application of the solution. Glycerol is a commonosmotic agent and a humectant and ophthalmic lubricant. It is applied tothe ocular surface to relieve irritation at concentrations ofapproximately 1%. Excessive addition of glycerol to the human eye maynot provide extended benefits for ocular lubrication. A long termophthalmic lubricant or vehicle, to protect the tear film and ocularsurface is needed. The present invention discloses a method of treating“dry eye” with compounds found in Harderian gland secretions.

SUMMARY OF THE INVENTION

New compositions which utilize compounds present in Harderian glandsecretions and a method of treating dry eye in a human in need thereofcomprising opthalmically administering an effective amount of a compoundpresent in Harderian gland secretions are disclosed herein.

In particular, the present invention relates to a method of treating dryeye, in a human in need thereof, comprising opthalmically administeringan effective amount of a compound present in the Harderian glandsecretions of rabbits.

Broadly, the present invention is directed to pharmaceuticalcompositions comprising compounds found in Harderian gland secretions, amethod of treating dry eye in a human comprising ophthalmicallyadministering an effective amount of a compound, e.g., a lipid compound,found in Harderian gland secretions, pharmaceutical compositionscomprising said lipid compounds, as identified by characteristicchemical data and mass spectra of said lipid compounds, said lipidcompound in essentially pure form, and an ophthalmic vehicle comprisinga therapeutic agent and a compound present in the secretions of theHarderian gland, e.g. a lipid compound, found in the secretions of theHarderian gland, e.g., a rabbit Harderian gland.

Thus, the present invention includes a method of treating dry eye in ahuman comprising ophthalmically administering an effective amount of alipid compound, found or present in the secretions of the Harderiangland.

The present invention further includes a pharmaceutical compositioncomprising a lipid compound, identified in the secretions of theHarderian gland, e.g., a rabbit Harderian gland.

The present invention further includes a compound identified by certaincharacteristic chemical data and mass spectra of the lipid compound(s)found in the secretions of the Harderian gland in its essentially pureform.

The present invention further includes an ophthalmic vehicle comprisingsaid Harderian lipid compound.

A further embodiment of the present invention relates to a method oftreating a patient suffering from “dry eye” and related ocular disordersto provide improved stability of the tear film of said patient with saidpharmaceutical composition or vehicle.

The present invention discloses new compositions related to theHarderian gland secretions and a method for using such compositions toeffectively administer therapeutic components to the eyes of a patientsuffering from an ocular disorder or disease.

The present invention may be employed in methods which compriseadministering the composition to a cornea of an eye, for example,contacting the composition with the cornea of the eye to prevent oralleviate ocular disorders or conditions.

The present invention includes one or more lipid compounds from theHarderian gland secretions effective, as a delivery vehicle to improveadministration of medicaments to the human eye by improving the tearfilm when mixed on the eye with tear fluid of a human with “dry eye”symptoms.

Alternatively, the lipid compound may be used to wet the dermal portionof the eyelid of a human eye after the composition is administered tothe human eye. For example, the present compositions may be effective towet a portion of the eyelid that is the junction between the conjunctivamucus membrane tissue and the dermis of the eyelid.

The overall higher molecular weight of the lipid compound from therabbit Harderian tear secretions compared to the tear secretions of thehuman provides, for example, an increased retention of the therapeuticcomponent on the cornea and into the eye.

Each of the lipid compounds obtained from the secretions of theHarderian gland has a different molecular weight resulting fromvariations on the saturated or unsaturated alkyl or alkenyl chainspresent in said lipid compound. The multiple alkyl and alkenyl chainchemistry of the lipid compounds includes one or more structuralcomponent portions, for example, having from 5 to 30 carbon atoms.Average molecular weights of the identified, saturated and unsaturatedcompounds which are components of the lipid compositions of theinvention may be about 500 amu or less.

In one very useful embodiment, the lipid compounds include a first etherester component portion having a first molecular weight, and a secondether ester component having a second, different, molecular weight.Preferably, the lipid compounds include five ether ester componentportions having different molecular weights. Advantageously, each of theether ester component portions may be present in an amount effective toprovide a pharmaceutical composition having an enhanced delivery of atherapeutic component to a patient, for example, when administered to acornea of a patient, relative to a substantially identical compositionwith no lipid compound.

Any suitable Harderian lipid compound may employed in accordance withthe present invention. Such lipid compound should be ophthalmicallyacceptable and compatible with the other components of the composition,and effective, in ophthalmically reasonable concentrations, tofacilitate administration of a therapeutic component to a patient whenadministered to an eye of the patient and to otherwise function inaccordance with the present invention.

In another useful embodiment, the present lipid compounds may be used asa delivery vehicle for any suitable therapeutic component.

Advantageously, the therapeutic components in the present Harderianlipid compound-containing vehicle are compatible with ocular tissue, andophthalmically acceptable.

The therapeutic component is selected to provide a desired therapeuticeffect to the eye and/or to another body part and/or systemically to thehuman or animal to whom the present composition is administered.

Additionally, because the lipid compound provides a vehicle for thetherapeutic medicament administered to the eye to actually pass through,or penetrate the cornea, rather than being washed away by the naturalprocesses of the eye, the present compositions may include a reducedquantity of the therapeutic component in a composition to obtain a giventherapeutic effect relative to a substantially identical compositionhaving no Harderian lipid compound. In general, the present compositionsprovide for more effective utilization of the therapeutic componentrelative to substantially identical compositions having no Harderiansecretion compounds. The vehicle or carrier component is ophthalmicallyacceptable and may include one or more lipid components which areeffective in providing such ophthalmic acceptability and/or otherwisebenefitting the composition and/or the eye to which the composition isadministered and/or the patient whose eye the composition isadministered to.

In addition to being useful for administering therapeutic components toa the eye of a patient, or to a patient through the eye of the patient,the present compositions can be effective to provide lubrication to aneye when administered to the eye, in the absence of a therapeuticcomponent for example, when administered to the human or animal eye asan artificial tear.

Methods of producing the present compositions include combining theHarderian secretions and/or lipid compounds with an ophthalmicallyacceptable carrier component and, if desired, the therapeutic component.

The present invention includes a Harderian lipid compound as anophthalmically acceptable vehicle component for delivering an effectiveamount of therapeutic medicaments to the eye. The invention features anew approach to managing keratoconjunctivitis sicca (KCS), dry eye, orSjogren's syndrome by topical application to the eye of a compositioncontaining a therapeutic amount of the Harderian secretion compound.

The present compositions can be solutions, although other forms, such asointments, gels, creams, emulsions, and the like may be employed.

Accordingly, in some embodiments, the present invention provides methodsof treating dry eye in a human in need thereof comprising opthalmicallyadministering an effective amount of a compound found in Harderian glandsecretions. In some embodiments, the compound is a lipid compound. Insome embodiments, the lipid compound is an ether ester compound.

In some embodiments, the compound has the formula:

wherein,R¹ is an unsubstituted alkyl or alkenyl;R² is an unsubstituted alkylL¹ is -L²-C(O)— L³- or —CH(-L⁴-R³)-L³-;L² is a bond or an unsubstituted alkylene;L³ and L⁴ are independently unsubstituted alkyleneR³ is a hydroxyl or —O—C(O)—R⁴ andR⁴ is unsubstituted alkyl.

In some embodiments, the compound has the formula:

In some embodiments, the compound has the formula:

With respect to the structures above, in some embodiments, R¹ isunsubstituted C₆-C₃₀ alkyl or alkenyl; R² is unsubstituted C₅-C₃₁ alkyl;and R⁴ is unsubstituted C₅-C₃₁ alkyl. In some embodiments, R¹ isunsubstituted C₁₄-C₂₂ alkyl or alkenyl; R² is unsubstituted C₁₃-C₁₇alkyl; and R⁴ is unsubstituted C₁₃-C₁₉ alkyl. In some embodiments, R² isan unsubstituted C₁₅ alkyl.

In some embodiments, the compound has the formula:

wherein: x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21,23, 25, 27 or 29; andw is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30. In someembodiments, x is 11, 13, or 15;y and z are independently 11, 13, 15 or 17; and w is 16, 18 or 20.

In some embodiments, the compound is selected from the group consistingof:

In some embodiments, the compound is administered in combination with atherapeutic agent. In some embodiments, the therapeutic agent isselected from the group consisting of: NMDA antagonists, antibacterials,antihistamines, decongestants, antiinflammatories, antiparasitics,miotics, sympathomimetics, anticholinergics, adrenergics, antivirals,local anesthetics, antifungals, amoebicidals, trichomonocidals,analgesics, mydriatics, antiglaucoma drugs, carbonic anhydraseinhibitors, ophthalmic diagnostic agents, ophthalmic agents used asadjuvants in surgery, chelating agents, antineoplastics,antihypertensives, muscle relaxants, diagnostics, adrenergicanesthetics, beta blockers, alpha-2-agonists, cycloplegics,postaglandins, derivatives thereof and mixtures thereof.

In some embodiments, the Harderian gland is a rabbit Harderian gland. Insome embodiments, the compound is administered topically.

In some embodiments, the compound is characterized by a mass spectrum(abscissa-mass-to-charge ratio m/z; ordinate-relative intensity) showingdetected component ions from a Harderian gland secretion sample from therabbit as shown in FIG. 1A. In some embodiments, the compound provides amass chromatogram (abscissa-time in minutes; ordinate-Selected IonMonitoring signal intensity) obtained from the HPLC liquidchromatography column separation of the Harderian secretion compounds atm/z 593, 791, 819, 847 as shown in FIG. 2 A, B, C, D. In someembodiments, the compound is characterized by a graph (abscissa-time inminutes; ordinate-signal intensity) showing TIC signals from the secondMS analyzer m/z=593, 791, 819, 847 obtained for the HPLC/MS/MS Harderiansecretion sample as shown in FIG. 3. In some embodiments, the Harderiangland lipid compound is characterized by HPLC/MS/MS mass spectra asshown in FIG. 4, wherein the parent ion and a plurality of fragment ionsresulting from fragmentation of the parent ion making a combination forfragment ions selected from the group comprising: m/z 593, 377, 338,319, 238; m/z 791, 551, 535, 317; m/z 819, 579, 563, 535, 479, 317; andm/z 847, 591, 563, 507, 317, 297. In some embodiments, the compoundcomprises parent ions having a particular m/z appearing in a massspectrum and a function of mass units indicating a strong signalcorresponding to molecular formula corresponding to the groupcomprising: C39H77O3, C51H99O5, C53H103O5, and C55H107O5 as shown inFIG. 5. In some embodiments, the compound has a chemical structurescorresponding to one of the structures shown in FIG. 5.

In some embodiments, the present invention provides methods of treatingdry eye in a human in need thereof comprising ophthalmicallyadministering an effective amount of a compound having the formula:

wherein, R¹ is an unsubstituted alkyl or alkenyl; R² is an unsubstitutedalkyl; L¹ is -L²-C(O)-L³- or —CH(-L⁴-R³)-L³-; L² is a bond or anunsubstituted alkylene; L³ and L⁴ are independently unsubstitutedalkylene; R³ is a hydroxyl or —O—C(O)—R⁴; and R⁴ is unsubstituted alkyl.In some embodiments, the compound has the formula:

In some embodiments, the compound has the formula:

In some embodiments, R¹ is unsubstituted C₆-C₃₀ alkyl or alkenyl; R² isunsubstituted C₅-C₃₁ alkyl; and R⁴ is unsubstituted C₅-C₃₁ alkyl. Insome embodiments, R¹ is unsubstituted C₁₄-C₂₂ alkyl or alkenyl; R² isunsubstituted C₁₃-C₁₇ alkyl; and R⁴ is unsubstituted C₁₃-C₁₉ alkyl. Insome embodiments, R² is an unsubstituted C₁₅ alkyl. In some embodiments,the compound has the formula:

wherein:x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27or 29; andw is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30. In someembodiments, x is 11, 13, or 15;y and z are independently 11, 13, 15 or 17; and w is 16, 18 or 20. Insome embodiments, the compound is selected from the group consisting of:

In some embodiments, the present invention provides a pharmaceuticalcomposition comprising a compound having the formula:

wherein, R¹ is an unsubstituted alkyl or alkenyl; R² is an unsubstitutedalkyl;L¹ is -L²-C(O)-L³- or —CH(-L⁴-R³)-L³-; L² is a bond or an unsubstitutedalkylene;L³ and L⁴ are independently unsubstituted alkylene; R³ is a hydroxyl or—O—C(O)—R⁴; andR⁴ is unsubstituted alkyl. In some embodiments, the compound has theformula:

In some embodiments, the compound has the formula:

In some embodiments, R¹ is unsubstituted C₆-C₃₀ alkyl or alkenyl; R² isunsubstituted C₅-C₃₁ alkyl; and R⁴ is unsubstituted C₅-C₃₁ alkyl. Insome embodiments, R¹ is unsubstituted C₁₄-C₂₂ alkyl or alkenyl; R² isunsubstituted C₁₃-C₁₇ alkyl; and R⁴ is unsubstituted C₁₃-C₁₉ alkyl. Insome embodiments, R² is an unsubstituted C₁₅ alkyl. In some embodiments,the compound has the formula:

wherein:x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27or 29; andw is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30. In someembodiments, x is 11, 13, or 15;y and z are independently 11, 13, 15 or 17; and w is 16, 18 or 20. Insome embodiments, the composition is selected from the group consistingof:

In some embodiments, the present invention provides a pharmaceuticalcomposition for treating dry eye in a human in need thereof comprisingan effective amount of a Harderian lipid compound obtained fromHarderian gland secretions combined with a therapeutic agent. In someembodiments, the therapeutic agent is selected from the group consistingof therapeutic component comprises a material selected from the groupconsisting of NMDA antagonists, antibacterials, antihistamines,decongestants, antiinflammatories, antiparasitics, miotics,sympathomimetics, anticholinergics, adrenergics, antivirals, localanesthetics, antifungals, amoebicidals, trichomonocidals, analgesics,mydriatics, antiglaucoma drugs, carbonic anhydrase inhibitors,ophthalmic diagnostic agents, ophthalmic agents used as adjuvants insurgery, chelating agents, antineoplastics, antihypertensives, musclerelaxants, diagnostics, adrenergic anesthetics, beta blockers,alpha-2-agonists, cycloplegics, postaglandins, derivatives thereof andmixtures thereof.

In some embodiments, the present invention provides a lipid compound inits essentially pure form having the following characteristics;

(a) mass spectra (abscissa-mass-to-charge ratio m/z; ordinate-relativeintensity) showing detected component ions from a Harderian secretionsample from the rabbit (FIG. 1A)(b) mass chromatogram (abscissa-time in minutes; ordinate-Selected IonMonitoring signal intensity) obtained from the HPLC liquidchromatography column separation of the Harderian secretion compounds atm/z 593, 791, 819, 847 as shown in FIG. 2A, B, C, D.(c) a graph (abscissa-time in minutes; ordinate-signal intensity)showing TIC signals from the second MS analyzer m/z=593, 791, 819, 847obtained for the HPLC/MS/MS Harderian secretion sample as shown in FIG.3.(d) HPLC/MS/MS mass spectra as shown in FIG. 4, wherein the parent ionand a plurality of fragment ions resulting from fragmentation of theparent ion making a combination for fragment ions selected from thegroup comprising:m/z 593, 377, 338, 319, 238m/z 791, 551, 535, 317m/z 819, 579, 563, 535, 479, 317; andm/z 847, 591, 563, 507, 317, 297.(e) parent ions having a particular m/z appearing in a mass spectrum anda function of mass units result in indicating a strong signalcorresponding to molecular formula corresponding to the groupcomprising: C39H77O3, C51H99O5, C53H103O5, and C55H107O5 as shown inFIG. 5.(f) A chemical structure corresponding to at least one of the structuresshown in FIG. 5.

In some embodiments, the present invention provides a lipid compound inits essentially pure form having the formula:

wherein,R¹ is an unsubstituted alkyl or alkenyl;R² is an unsubstituted alkyl;L¹ is -L²-C(O)-L³- or —CH(-L⁴-R³)-L³-;L² is a bond or an unsubstituted alkylene;L³ and L⁴ are independently unsubstituted alkyleneR³ is a hydroxyl or —O—C(O)—R⁴; andR⁴ is unsubstituted alkyl.

In some embodiments, the lipid compound has the formula:

In some embodiments, the lipid compound has the formula:

In some embodiments, R¹ is unsubstituted C₆-C₃₀ alkyl or alkenyl; R² isunsubstituted C₅-C₃₁ alkyl; and R⁴ is unsubstituted C₅-C₃₁ alkyl. Insome embodiments, R¹ is unsubstituted C₁₄-C₂₂ alkyl or alkenyl; R² isunsubstituted C₁₃-C₁₇ alkyl; and R⁴ is unsubstituted C₁₃-C₁₉ alkyl. Insome embodiments, R² is an unsubstituted C₁₅ alkyl. In some embodiments,the lipid compound has the formula:

Wherein x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21,23, 25, 27 or 29; and

w is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30. In someembodiments, x is 11, 13, or 15;y and z are independently 11, 13, 15 or 17; and w is 16, 18 or 20. Insome embodiments, the lipid compound formula is selected from the groupconsisting of:

In some embodiments, the present invention provides, an ophthalmicvehicle comprising a Harderian lipid compound. In some embodiments, theHarderian lipid compound is an ether ester compound. In someembodiments, the ether ester compound is a dietherester compound. Insome embodiments, the Harderian lipid compound has the formula:

wherein, R¹ is an unsubstituted alkyl or alkenyl; R² is an unsubstitutedalkyl;L¹ is -L²-C(O)-L³- or —CH(-L⁴-R³)-L³-; L² is a bond or an unsubstitutedalkylene;L³ and L⁴ are independently unsubstituted alkylene; R³ is a hydroxyl or—O—C(O)—R⁴; andR⁴ is unsubstituted alkyl. In some embodiments, the Harderian lipidcompound has the formula:

In some embodiments, the Harderian lipid compound has the formula:

In some embodiments, R¹ is unsubstituted C₆-C₃₀ alkyl or alkenyl; R² isunsubstituted C₅-C₃₁ alkyl; and R⁴ is unsubstituted C₅-C₃₁ alkyl. Insome embodiments, R¹ is unsubstituted C₁₄-C₂₂ alkyl or alkenyl; R² isunsubstituted C₁₃-C₁₇ alkyl; and R⁴ is unsubstituted C₁₃-C₁₉ alkyl. Insome embodiments, R² is an unsubstituted C₁₅ alkyl. In some embodiments,the compound further comprises:

wherein x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21,23, 25, 27 or 29; andw is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30. In someembodiments, x is 11, 13, or 15;y and z are independently 11, 13, 15 or 17; and w is 16, 18 or 20.

In some embodiments, the compound has the formula:

In some embodiments, the combination of the Harderian compound and thetherapeutic agent is more effective when administered to the eye torelieve symptoms of dry eye relative to an identical composition withoutthe Harderian lipid compound.

In some embodiments, the methods for treating dry eye in a human in needthereof comprise opthalmically administering an effective amount oflipid composition improving dry eye of a human in need of suchimprovement, thereby providing at least one additional benefit to theeye.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIGS. 1 A & B illustrate ESI mass spectra (abscissa-mass-to-charge ratiom/z; ordinate-relative intensity) showing detected component parent,fragment, and quasi-molecular ions [M+H]⁺, of a Harderian secretionsample from the rabbit (FIG. 1A) and from a human tear sample (FIG. 1B).

FIGS. 2 A, B, C, D illustrate a HPLC/MS chromatogram (abscissa-time inminutes; ordinate-Selected Ion Monitoring signal intensity) obtainedfrom the HPLC liquid chromatography column separation of the Harderiansecretion compounds at m/z=593, 791, 819, 847.

FIG. 3 is a graph (abscissa-time in minutes; ordinate-signal intensity)showing TIC signals from the second MS analyzer m/z=593, 791, 819, 847obtained for the HPLC/MS/MS Harderian secretion sample. The data hereare complimentary to the data of FIG. 2.

FIG. 4 shows ESI/APICI MS/MS mass spectral fragmentation traces(abscissa-mass-to-charge ratio m/z; ordinate-relative intensity) forHarderian secretion compounds at m/z=593, 791, 819, 847.

FIG. 5 shows characterization data including molecular weight andstructural identification for five Harderian secretion compounds.

DETAILED DESCRIPTION Definitions

“Alkyl” refers to a monovalent straight-chain, branched or cyclicsaturated aliphatic hydrocarbon radical. Preferably, the alkyl group isa straight chain radical having 1 to 40 carbon atoms. More preferably,it is an alkyl radical of from 5 to 31 carbon atoms, most preferably 13to 17 carbon atoms. Typical alkyl radicals include pentyl, hexyl,tridecanyl, tetradecanyl, nonadecanyl, docosanyl, triacontanyl,hentriacontanyl and the like. Preferably this term denotes an acycliccarbon or a saturated acyclic carbon chain represented by the formulaCnH2n+1 wherein n is an integer of from 1 to 31.

“Alkenyl” refers to a monovalent, straight-chain, branched or cyclic,unsaturated aliphatic hydrocarbon radical having one or more, preferablyone, double bond. Preferably, the alkenyl radical has from 2 to 40carbon atoms. More preferably, it is an alkenyl radical of from 6 to 30carbon atoms, most preferably 14 to 22 carbon atoms. Typical alkenylgroups include hexenyl, tridecenyl, tetradecenyl, nonadecenyl,docosenyl, triacontenyl, hentriacontenyl and the like. Preferably thisterm denotes an acyclic carbon chain which contains a carbon-to-carbondouble bond and is represented by the formula CnH2n−1 wherein n is aninteger of from 2 to 40.

“Alkylene” refers to a divalent, straight-chain, branched or cyclic,saturated aliphatic hydrocarbon radical. Preferably, the alkylene grouphas from 1 to 12 carbon atoms. This term denotes an acyclic carbon or asaturated acyclic carbon chain represented by the formula CnH2n−2wherein n is an integer of from 1 to 12. More preferably, it is a loweralkylene of from 1 to 7 carbon atoms, most preferably from 1 to 4 carbonatoms, e.g., methylene.

As used herein, the term “lipid” refers to water-insoluble organicsubstances naturally found in cells that are extractable by nonpolarsolvents such as chloroform, ether, or benzene. Lipids generally servefour general functions: (1) as structural components of membranes; (2)as intracellular storage depots of metabolic fuel; (3) as a transportform of metabolic fuel; and (4) as protective components of cell wallsof many organisms. Some examples of natural lipids are long-chain fattyacids, fatty acid esters, acylglycerols, phosphoglycerides, steroids,waxes, terpenes, and fat-soluble vitamins

As used herein, the term “mass-to-charge ratio” refers to the ratio ofthe mass of a detected fragment in a mass spectrometer over the chargeof that same detected fragment. The mass-to-charge ratio is abbreviatedas m/z.

As used herein, the term MS refers to “mass spectrometry” and relatedvariations on the word “spectrometry” where one of skill in the art willappreciate the words are also appropriate.

As used herein, the term MW refers to “molecular weight” and relatedvariations of atomic mass units used in mass spectrometry where one ofskill in the art will appreciate the other units are al so appropriate.

As used herein, the term chemical formula includes information about thespatial arrangement of bonds in a chemical but not necessarily the exactisomer; while the term molecular formula refers to the number of atomsof each element in the compound.

As used herein, the term “analytical technique” refers to a method fordeterring a property of a particular substance. Preferred analyticaltechniques include those having an ionizing source, such as for example,mass spectrometry. One of skill in the art will appreciate that otheranalytical techniques can be used in the instant invention.

Liquid chromatography is commonly used as a means of physicallyseparating compounds in a mixture and is used to purify, quantify, andidentify individual components of the mixture. High pressure liquidchromatography (HPLC), approximately 40 MPa, utilizes a stationary phaseof particles, approximately 2-5 um in diameter, densely packed in a 1-2mm separatory column, a pump that moves the mobile phase and compoundthrough the stationary phase, and a detector that provides acharacteristic retention time for the eluted compounds. The detector mayalso provide characteristic data for each compound such as anultraviolet-visible spectrum, fluorescence detection, or data from amass spectrometer. The retention time of the compounds in the mixturedepends on the strength of the interaction with the stationary phase.

Normal phase HPLC refers to a method or separating compounds based onadsorption to a stationary surface and by polarity: the most nonpolarcompounds elude first and the most polar compounds elute last. Thenormal stationary phase is polar, while a non-polar, non-aqueous mobilephase work to separating compounds in non-polar solvents. The use ofmore polar solvents or gradient elution mixtures of solvents, such asmiscible combinations of water, methanol and acetonitrile, in the mobilephase decreases the retention time of the compounds where use of morehydrophobic solvents increases retention times.

The eluent from the liquid chromatography column can then be detectedand the separated components can be mass analyzed. The analysis can beperformed online, by feeding the liquid eluting from the LC columndirectly to an electrospray, or offline, by collecting fractions to belater analyzed in an electrospray-mass spectrometry setup.

Electrospray is a gentle technique for ionizing molecules and leads to(quasi-) molecular ions. Electrospray ionization (ESI) is a techniqueused in mass spectrometry to produce ions. It is especially useful inproducing ions from macromolecules because it overcomes the propensityof these molecules to fragment when ionized.

The ions observed by ESI mass spectrometry may be quasimolecular ionscreated by the addition of a proton (a hydrogen ion) and denoted [M+H]⁺,or of another cation such as sodium ion, [M+Na]⁺, or the removal of aproton, [M−H]⁻. Multiply-charged ions such as [M+nH]^(n+), wherein n isan integer, are often observed. For large macromolecules, there can bemany charge states, resulting in a characteristic charge state envelope.All these are even-electron ion species: electrons (alone) are not addedor removed, unlike in some other ionization sources. The analytes aresometimes involved in electrochemical processes, leading to shifts ofthe corresponding peaks in the mass spectrum.

As used herein, the term “total ion chromatogram or TIC” refers to thegraph (abscissa-time in minutes; ordinate-ion signal intensity) showinga total ion signal or full scan obtained for the sample by a massspectrometer detector. As used herein, the term “scanning or single ionmonitoring” spectrometer refers to ions of the selected mass-to-chargeratio m/z to pass to the output port of the mass filter. Select scanningor single ion monitoring may be used to select ions of particular m/z,or a range of m/z ions, forming a plurality of ions generated by thesource and is used to located particular ions within that m/z rangespecified or to select single ion m/z in what is referred to as selector single ion monitoring (SIM). Typically the ion detector collects theions and converts them to a signal to measure the intensity of the ionsas a computer display, typically as a graph (abscissa-time in minutes;ordinate-signal intensity) showing a signal specified. One of skill inthe art will appreciate that other analytical techniques can be used inthe instant invention.

As used herein, the term “high-pressure liquid chromatography tandemmass spectrometry” refers to a mass spectrometry technique that is knownto one of skill in the art and involves obtaining a sample from ahigh-pressure liquid chromatograph system utilized to separate compoundsfrom compound mixtures and deliver a liquid sample to a massspectrometer sample inlet. The sample is ionized in the massspectrometer coupling two stages of mass analysis so as to subject aparticular fragment of a first ionization process to a subsequentionization process. Tandem mass spectrometers operate by using theseparation of ions as a first fractionation step. Before entering thesecond mass spectrometer, ion fractions from the first MS analyzer arefragmented, usually by passage through a neutral collision gas to inducefragmentation, to a second MS analyzer. These fragment ions exist as asubset of the original parent ions. Analysis of m/z spectrum of thesesubset ions are used to determine fragmentation patterns withoutinterference from other ion fractions. The device handling system isoperably connected to the mass spectrometer under the direction ofcomputer control. One skilled in the art will appreciate that otheranalytical techniques can be used in the instant invention.

The Harderian lipid compound may be represented as:

wherein,R¹ is an unsubstituted alkyl or alkenyl;R² is an unsubstituted alkylL¹ is -L²-C(O)-L³- or —CH(-L⁴-R³)-L³-;L² is a bond or an unsubstituted alkylene;L³ and L⁴ are independently unsubstituted alkylene;R³ is a hydroxyl or —O—C(O)—R⁴; andR⁴ is unsubstituted alkyl.

The Harderian lipid compounds of Formula I are related by a basicchemical structure represented by:

where R¹ is unsubstituted C₆-C₃₀ alkyl or alkenyl; R² is unsubstitutedC₅-C₃₁ alkyl; and R⁴ is unsubstituted C₅-C₃₁ alkyl. Alternatively, R¹ isunsubstituted C₁₄-C₂₂ alkyl or alkenyl; R² is unsubstituted C₁₃-C₁₇alkyl; and R⁴ is unsubstituted C₁₃-C₁₉ alkyl. More preferably, R² is anunsubstituted C₁₅ alkyl.

The preferred compounds of formula IV are

wherein the alkyl units are as follows:x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27or 29; and w is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30 andalternatively, wherein x is 11, 13, or 15; y and z are independently 11,13, 15 or 17; and w is 16, 18 or 20.

As used herein, these compounds are related by a basic chemicalstructure represented by

The above compounds may be isolated from Harderian gland secretions orsynthesized by methods known in the art, e.g., by solvent extraction ofa lipid component from the secretions of the Harderian gland followed,if desired by chromatographic separation of the individual compoundscomprising said solvent-extracted lipid component.

The Harderian lipid compounds may be administered to a patient needingtreatment for dry eye in combination with a opthalmically-acceptablevehicle or carrier. Other components, which may be included in thecarrier components include, without limitation, buffer components,tonicity components, preservative-components, pH adjustors, componentscommonly found in artificial tears, such as one or more electrolytes,and the like and mixtures thereof. In one very useful embodiment thecarrier component includes at least one of the following: an effectiveamount of a buffer component; an effective amount of a tonicitycomponent; an effective amount of is a preservative component; andwater.

These additional components preferably are ophthalmically acceptable andcan be chosen from materials which are conventionally employed inophthalmic compositions, for example, compositions used to treat eyesafflicted with dry eye syndrome, artificial tear formulations and thelike.

Acceptable effective concentrations for these additional components inthe compositions of the invention are readily apparent to the skilledpractitioner.

Said compounds may be administered, alone, or in combination withpharmaceutically acceptable substances including buffer solutions, forexample phosphate buffered saline, or inert carrier compounds,glycerols, mineral oils or similar substances to the ocular surface ofthe eye.

The dosage of the above lipid compounds is optimized according to theformulation and method of delivery and the mode of administration isdetermined by conventional protocols and effectively treats “dry eye”symptoms in humans.

Said Harderian lipid compound may be utilized as a vehicle for topicaladministration of a therapeutic medicament. In particular, saidHarderian lipid compound-containing vehicle is used to deliver anydesired therapeutic agent, or combination of therapeutic agents,including an antibiotic agent, an antiviral agent, an antifungal agent,an anti-cancer agent, an antiglaucoma agent, an antiinflammatory agent,an analgesic, an immunomodulatory agent, a macro-molecule, or a mixturethereof.

Therapeutic agents that are used in the method of the present inventioninclude, but are not limited to NMDA antagonists, antihistamines,antiparasitics, miotics, sympathomimetics, anticholinergics, localanesthetics, amoebicidals, trichomonocidals, mydriatics, carbonicanhydrase inhibitors, ophthalmic diagnostic agents, ophthalmic agentsused as adjuvants in surgery, chelating agents, antineoplastics,diagnostics, adrenergic anesthetics, beta blockers, alpha-2-agonists,cycloplegics, prostaglandins, ace-inhibitors, endogenous cytokines,agents that influence basement membrane, agents that influence thegrowth of endothelial cells, adrenergic agonists or blockers,cholinergic agonists or blockers, aldose reductase inhibitors,analgesics, anesthetics, antiallergics, anti-inflammatory agents,antihypertensives, pressors, antibacterials, antivirals, antifungals,antiprotozoals, anti-infectives, antitumor agents, antimetabolites,antiangiogenic agents, tyrosine kinase inhibitors, antibiotics such asaminoglycosides such as gentamycin, kanamycin, neomycin, and vancomycin;amphenicols such as chloramphenicol; cephalosporins, such as cefazolinHCl; penicillins such as ampicillin, penicillin, carbenicillin,oxycillin, methicillin; lincosamides such as lincomycin; polypeptideantibiotics such as polymixin and bacitracin; tetracyclines such astetracycline; quinolones such as ciproflaxin, etc.; sulfonamides such aschloramine T; and sulfones such as sulfanilic acid as the hydrophilicentity, anti-viral drugs, e.g. acyclovir, gancyclovir, vidarabine,azidothymidine, dideoxyinosine, dideoxycytosine, dexamethasone,ciproflaxin, water soluble antibiotics, such as acyclovir, gancyclovir,vidarabine, azidothymidine, dideoxyinosine, dideoxycytosine;epinephrine; isoflurphate; adriamycin; bleomycin; mitomycin; ara-C;actinomycin D; scopolamine; and the like, analgesics, such as codeine,morphine, keterolac, naproxen, etc., an anesthetic, e.g. lidocaine;.beta.-adrenergic blocker or .beta.-adrenergic agonist, e.g. ephidrine,epinephrine, etc.;

aldose reductase inhibitor, e.g. epalrestat, ponalrestat, sorbinil,tolrestat; antiallergic, e.g. cromolyn, beclomethasone, dexamethasone,and flunisolide; colchicine; antiamebic agents, e.g. chloroquine andchlortetracycline; and antifungal agents, e.g. amphotericin, etc.,anti-angiogenesis compounds such as anecortave acetate, anti-glaucomaagents, such as brimonidine, acetozolamide, bimatoprost, Timolol,mebefunolol; memantine; alpha-2 adrenergic receptor agonists; 2ME2;anti-neoplastics, such as vinblastine, vincristine, interferons; alpha.,beta. and .gamma., antimetabolites, such as folic acid analogs, purineanalogs, and pyrimidine analogs; immunosuppressants such as azathiprine,cyclosporine and mizoribine; miotic agents, such as carbachol, mydriaticagents such as atropine, etc., protease inhibitors such as aprotinin,camostat, gabexate, vasodilators such as bradykinin, etc., and variousgrowth factors, such epidermal growth factor, basic fibroblast growthfactor, nerve growth factors, and the like, including derivativesthereof and mixtures thereof.

These and other aspects, objects, and embodiments will be more apparentin the accompanying specific examples and drawing figures.

Example 1

Harderian lipids tear secretions are collected from living rabbits andextracts are made from rabbit Harderian glands. Control tear secretionsare collected from normal human subjects as opposed to human subjectsthat are suffering from dry eye. These samples were analyzed byESI-CI/MS/MS and are represented as the Harderian sample in FIG. 1A andthe human tear sample in FIG. 1B. Comparing the mass spectra of FIG. 1Aand FIG. 1B, the Harderian compound at m/z=593, and the plurality ofrelated compounds, are not found in the human spectral sample.

The lipids are initially separated from the Haderian gland secretions ofrabbits by normal phase HPLC separation followed immediately by massspectrometry using chemical ionization of the separated lipid(HPLC/ESI-CI/MS/MS) as shown in FIG. 2. Four compounds identified bythis process are unique to rabbits and are thought to have their originsin the Harderian gland and their spectral patterns are further isolatedby MS/MS techniques as shown in FIGS. 3-4. The mass fragmentationpatterns of the separated lipids indicate they are structurally relatedto each other and to chemical structure m/z=593.

In the case of the compound at m/z=593, a standard based on thetheoretical structure is synthesized, and the fragmentation pattern ofthe standard confirms the theoretical structure of the isolated lipid itwas based upon.

Quasi molecular ions are inferred with use of ESI/API-CI/MS/MStechniques with an addition of a proton (a hydrogen ion) and denoted[M+H]⁺, or the removal of a proton, [M−H]⁻. Multiply-charged ions suchas [M+nH]^(n+) are often observed. This leads to shifts of thecorresponding peaks in the mass spectrum. Therefore, the ions from theHarderian rabbit gland secretions may have molecular weights within arange of atomic mass units which includes a hydrogen ion. The depictionof this variable is taken into account during the analytical scans asshown in FIGS. 2-4.

The mass spectrometric analysis of the rabbit Harderian gland secretionsare characterized by HPLC/MS/MS mass spectrometry wherein the parent ionand a plurality of fragment ions, quasi molecular ions, molecularweights, and molecular formula are identified as follows:

-   -   m/z=791, 551, 535, 317    -   MW [M+H]⁺=791    -   molecular formula=C51H99O5    -   retention time 22.2 min

-   -   m/z=819, 579, 563, 535, 479, 317    -   MW [M+H]⁺=891    -   molecular formula=C53H103O5    -   HPLCMS retention time=23.8 min

-   -   m/z=847, 591, 563, 507, 317, 297    -   MW [M+H]⁺=847    -   molecular formula=C55H107O5    -   HPLCMS retention time=25.4 min

-   -   m/z=593, 377, 338, 319, 238    -   MW [M+H]⁺=593    -   molecular formula=C39H77O3    -   HPLC retention times=6.9, 16.7, 22.2, 23.8 min

-   -   MW=611    -   molecular formula=C39H79O4    -   hydrolyzed form of MW=593

Mass spectra of the above lipid compounds may also appear in hydrolyzed,dehydrolyzed, and/or rearrangements of unsaturated functional groups.For example, the unstable Harderian compound at m/z=611 mayalternatively be represented as chemically ionized or in its dehydratedform as MW=593, for example, R1 is a C20 alkyl group and R2 is a C13alkyl group. It is also possible the compound at m/z=593 has severalchemically structurally related forms with alternative functional groupsas it has four HPLC retention times and coelutes with two of the otherHarderian compounds.

Example 2

The Harderian gland secretion or tears from a rabbit containingidentified HPLC/MS/MS compound m/z=593 is ophthalmically administered inan effective amount to treat “dry eye” of a human. The quantified amountof the compound m/z=593 is comparable to the quantified amount of lipidin the human tear sample represented by FIG. 1B. The effective amount ofthe compound is specified by routine methods and is administered incombination with pharmaceutically acceptable substances including buffersolutions, for example phosphate buffered saline, or inert carriercompounds, glycerols, mineral oils or similar substances to the ocularsurface of the eye. The dosage of rabbit Harderian gland secretionincluding the compound m/z=593 is optimized according to the formulationand method of delivery and the mode of administration is determined byconventional protocols and effectively treats “dry eye” symptoms inhumans.

A second pharmaceutical composition comprising the Harderian glandsecretion or tears from a rabbit containing identified HPLC/MS/MScompounds, including the compound m/z=593, is ophthalmicallyadministered in an effective amount to treat “dry eye” of a human. Thequantified amount of the compounds identified in FIG. 1A is comparableto the quantified amount of lipid in the human tear sample representedby FIG. 1B. The effective amount of the compound is specified by routinemethods and is administered in combination with pharmaceuticallyacceptable substances including buffer solutions, for example phosphatebuffered saline, or inert carrier compounds, glycerols, mineral oils orsimilar substances to the ocular surface of the eye. The dosage ofrabbit Harderian gland secretion including the identified compoundsincluding compound m/z=593 is optimized according to the formulation andmethod of delivery and the mode of administration is determined byconventional protocols and effectively treats “dry eye” symptoms inhumans.

The results of testing the effect of the identified representativeHarderian lipid compounds indicate all are effective in treating “dryeye” conditions of humans, although to various degrees.

Example 3

A new composition related to the Harderian gland secretions issynthesized based on the theoretical structure and the fragmentationpattern of the standard confirms the theoretical structure of theisolated lipid m/z=593 upon which it is based.

The effective amount of the synthesized compound administered isspecified by routine methods and is administered, in combination withpharmaceutically acceptable substances including buffer solutions, forexample phosphate buffered saline, or inert carrier compounds,glycerols, mineral oils or similar substances, to the ocular surface ofthe eye. The dosage of rabbit Harderian gland secretion including thesynthesized compound is optimized according to the formulation andmethod of delivery and the mode of administration is determined byconventional protocols and effectively treats “dry eye” symptoms inhumans.

A second composition related to the Harderian gland secretions issynthesized including the plurality of lipid compounds in Example 1. Theeffective amount of the plurality of lipid compounds administered isspecified by routine methods and is administered, in combination withpharmaceutically acceptable substances including buffer solutions, forexample phosphate buffered saline, or inert carrier compounds,glycerols, mineral oils or similar substances, to the ocular surface ofthe eye. The dosage of said second composition is optimized according tothe formulation and method of delivery and the mode of administration isdetermined by conventional protocols and effectively treats “dry eye”symptoms in humans.

The results of testing the effect of the synthetic representativeHarderian compounds indicate all are effective in treating “dry eye”conditions of humans, although to various degrees.

Example 4

The present invention further includes an ophthalmic vehicle comprisingone or more of said Harderian lipid compounds. The vehicle comprisesquantified amounts of the compound containing m/z=593 and the compoundsrelated to m/z=791, 819, 847 (FIG. 1A), either as obtained fromHanderian gland secretions or synthesized, and may be comparable to thequantified amount of lipid in the human tear sample represented by FIG.1B to treat “dry eye” symptoms of a human.

The effective amount of said Harderian lipid compounds administered as avehicle is specified by routine methods and may be combined withpharmaceutically acceptable substances utilized in ophthalmic vehicles,including buffer solutions, for example phosphate buffered saline, orinert carrier compounds, glycerols, mineral oils or similar substances.The dosage of said Harderian lipid compound is optimized according tothe formulation and method of delivery and the mode of administrationare determined by conventional protocols to effectively treat “dry eye”symptoms in humans.

Said Harderian lipid compound-containing vehicle is administeredtopically, e.g. as an eye drop, to provide “artificial tears.”

Said Harderian lipid compound-containing vehicle is used in a method oftreating a patient suffering from “dry eye” and related ocular disordersto provide improved stability of the tear film of a patient in need ofsaid treatment.

Said Harderian lipid compound may be utilized as a vehicle for topicaladministration of a therapeutic medicament. In particular, saidHarderian lipid compound-containing vehicle is used to deliver anydesired therapeutic agent, or combination of therapeutic agents,including an antibiotic agent, an antiviral agent, an antifungal agent,an anti-cancer agent, an antiglaucoma agent, an antiinflammatory agent,an analgesic, an immunomodulatory agent, a macro-molecule, or a mixturethereof.

Therapeutic agents that are used in the method of the present inventioninclude, but are not limited to NMDA antagonists, antihistamines,antiparasitics, miotics, sympathomimetics, anticholinergics, localanesthetics, amoebicidals, trichomonocidals, mydriatics, carbonicanhydrase inhibitors, ophthalmic diagnostic agents, ophthalmic agentsused as adjuvants in surgery, chelating agents, antineoplastics,diagnostics, adrenergic anesthetics, beta blockers, alpha-2-agonists,cycloplegics, prostaglandins, ace-inhibitors, endogenous cytokines,agents that influence basement membrane, agents that influence thegrowth of endothelial cells, adrenergic agonists or blockers,cholinergic agonists or blockers, aldose reductase inhibitors,analgesics, anesthetics, antiallergics, anti-inflammatory agents,antihypertensives, pressors, antibacterials, antivirals, antifungals,antiprotozoals, anti-infectives, antitumor agents, antimetabolites,antiangiogenic agents, tyrosine kinase inhibitors, antibiotics such asaminoglycosides such as gentamycin, kanamycin, neomycin, and vancomycin;amphenicols such as chloramphenicol; cephalosporins, such as cefazolinHCl; penicillins such as ampicillin, penicillin, carbenicillin,oxycillin, methicillin; lincosamides such as lincomycin; polypeptideantibiotics such as polymixin and bacitracin; tetracyclines such astetracycline; quinolones such as ciproflaxin, etc.; sulfonamides such aschloramine T; and sulfones such as sulfanilic acid as the hydrophilicentity, anti-viral drugs, e.g. acyclovir, gancyclovir, vidarabine,azidothymidine, dideoxyinosine, dideoxycytosine, dexamethasone,ciproflaxin, water soluble antibiotics, such as acyclovir, gancyclovir,vidarabine, azidothymidine, dideoxyinosine, dideoxycytosine;epinephrine; isoflurphate; adriamycin; bleomycin; mitomycin; ara-C;actinomycin D; scopolamine; and the like, analgesics, such as codeine,morphine, keterolac, naproxen, etc., an anesthetic, e.g. lidocaine;.beta.-adrenergic blocker or .beta.-adrenergic agonist, e.g. ephidrine,epinephrine, etc.; aldose reductase inhibitor, e.g. epalrestat,ponalrestat, sorbinil, tolrestat; antiallergic, e.g. cromolyn,beclomethasone, dexamethasone, and flunisolide; colchicine; antiamebicagents, e.g. chloroquine and chlortetracycline; and antifungal agents,e.g. amphotericin, etc., anti-angiogenesis compounds such as anecortaveacetate, anti-glaucoma agents, such as brimonidine, acetozolamide,bimatoprost, Timolol, mebefunolol; memantine; alpha-2 adrenergicreceptor agonists; 2ME2; anti-neoplastics, such as vinblastine,vincristine, interferons; alpha., beta. and .gamma., antimetabolites,such as folic acid analogs, purine analogs, and pyrimidine analogs;immunosuppressants such as azathiprine, cyclosporine and mizoribine;miotic agents, such as carbachol, mydriatic agents such as atropine,etc., protease inhibitors such as aprotinin, camostat, gabexate,vasodilators such as bradykinin, etc., and various growth factors, suchepidermal growth factor, basic fibroblast growth factor, nerve growthfactors, and the like, including derivatives thereof and mixturesthereof.

The present invention is not to be limited in scope by the exemplifiedembodiments, which are only intended as illustrations of specificaspects of the invention. Although there is described hereinabove aspecific method of treating dry eye with compounds obtained fromHarderian gland secretions in accordance with the present invention forthe purpose of illustrating the manner in which the invention can beused to advantage, it will be appreciated that the invention is notlimited thereto. For example, the methods and compositions of thepresent invention may be used to treat other ocular conditions anddisorders, especially when the compounds found in Harderian glandsecretions are utilized as a vehicle for a therapeutic agent, asdescribed above. Accordingly, any and all variations and modificationswhich may occur to those skilled in the art are to be considered to bewithin the scope and spirit of the invention as defined in the appendedclaims.

What is claimed is:
 1. An ophthalmic vehicle comprising a compoundhaving the formula:

wherein: R¹ is an unsubstituted C₆-C₃₀ alkyl or alkenyl; R² is anunsubstituted C₅-C₃₁ alkyl; L¹ is -L²-C(O)-L³- or —CH(-L⁴-R³)-L³-; L² isa bond or an unsubstituted alkylene; L³ and L⁴ are independentlyunsubstituted alkylene; R³ is a hydroxyl or —O—C(O)—R⁴; and R⁴ is anunsubstituted C₅-C₃₁ alkyl; and said ophthalmic vehicle furthercomprising at least one additive selected from the group consisting ofbuffer components, tonicity components, preservative components, pHadjustor components, electrolytes, and combinations thereof.
 2. Theophthalmic vehicle of claim 1, wherein: R¹ is an unsubstituted C₁₄-C₂₂alkyl or alkenyl; R² is an unsubstituted C₁₃-C₁₇ alkyl; and R⁴ is anunsubstituted C₁₃-C₁₉ alkyl.
 3. The ophthalmic vehicle of claim 2,wherein R² is an unsubstituted C₁₅ alkyl.
 4. The ophthalmic vehicle ofclaim 1, wherein the compound has the formula:

wherein: x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21,23, 25, 27 or 29; and w is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or30.
 5. The ophthalmic vehicle of claim 4, wherein: x is 11, 13, or 15; yand z are independently 11, 13, 15 or 17; and w is 16, 18 or
 20. 6. Theophthalmic vehicle of claim 5, wherein said compound is selected fromthe group consisting of:


7. The ophthalmic vehicle of claim 1, further comprising a therapeuticagent is selected from the group consisting of NMDA antagonists,antibacterials, antihistamines, decongestants, antiinflammatories,antiparasitics, miotics, sympathomimetics, anticholinergics,adrenergics, antivirals, local anesthetics, antifungals, amoebicidals,trichomonocidals, analgesics, mydriatics, antiglaucoma drugs, carbonicanhydrase inhibitors, ophthalmic diagnostic agents, ophthalmic agentsused as adjuvants in surgery, chelating agents, antineoplastics,antihypertensives, muscle relaxants, diagnostics, adrenergicanesthetics, beta blockers, alpha-2-agonists, cycloplegics,prostaglandins and derivatives thereof.
 8. A pharmaceutical compositioncomprising a compound having the formula:

wherein: R¹ is an unsubstituted C6-C₃₀ alkyl or alkenyl; R² is anunsubstituted C₅-C₃₁ alkyl; L¹ is -L²-C(O)-L³- or —CH(-L⁴-R³)-L³-; L² isa bond or an unsubstituted alkylene; L³ and L⁴ are independentlyunsubstituted alkylene; R³ is a hydroxyl or —O—C(O)—R⁴; and R⁴ is anunsubstituted C₅-C₃₁ alkyl; and a pharmaceutically acceptable carrier.9. The pharmaceutical composition of claim 8, wherein: R¹ is anunsubstituted C₁₄-C₂₂ alkyl or alkenyl; R² is an unsubstituted C₁₃-C₁₇alkyl; and R⁴ is an unsubstituted C₁₃-C₁₉ alkyl.
 10. The pharmaceuticalcomposition of claim 9, wherein R² is an unsubstituted C₁₅ alkyl. 11.The pharmaceutical composition of claim 8, wherein the compound has theformula:

wherein: x, y and z are independently 5, 7, 9, 11, 13, 15, 17, 19, 21,23, 25, 27 or 29; and w is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or30.
 12. The pharmaceutical composition of claim 11, wherein: x is 11,13, or 15; y and z are independently 11, 13, 15 or 17; and w is 16, 18or
 20. 13. The pharmaceutical composition of claim 11, wherein saidcompound is selected from the group consisting of:


14. The pharmaceutical composition of claim 8, further comprising atherapeutic agent is selected from the group consisting of NMDAantagonists, antibacterials, antihistamines, decongestants,antiinflammatories, antiparasitics, miotics, sympathomimetics,anticholinergics, adrenergics, antivirals, local anesthetics,antifungals, amoebicidals, trichomonocidals, analgesics, mydriatics,antiglaucoma drugs, carbonic anhydrase inhibitors, ophthalmic diagnosticagents, ophthalmic agents used as adjuvants in surgery, chelatingagents, antineoplastics, antihypertensives, muscle relaxants,diagnostics, adrenergic anesthetics, beta blockers, alpha-2-agonists,cycloplegics, prostaglandins and derivatives thereof.